fixes #14331

lib/pure/quitprocs.nim

@@ -0,0 +1,28 @@
+#
+#
+#            Nim's Runtime Library
+#        (c) Copyright 2016 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## ``system.addQuitProc`` is nice and very useful but due to its C-based
+## implementation it doesn't support closures which limits its usefulness.
+## This module fixes this. Later versions of this module will also
+## support the JavaScript backend.
+
+var
+  gClosures: seq[proc () {.closure.}]
+
+proc callClosures() {.noconv.} =
+  for i in countdown(gClosures.len-1, 0):
+    gClosures[i]()
+
+proc addQuitClosure*(cl: proc () {.closure.}) =
+  ## Like ``system.addQuitProc`` but it supports closures.
+  if gClosures.len == 0:
+    addQuitProc(callClosures)
+    gClosures = @[cl]
+  else:
+    gClosures.add(cl)